Process for resolving petroleum emulsions



1 UNITED STATES PATENT OFFICE PROCESS FOR RESOLVING PETROLEUM EMULSIONS Melvin De Groote, University City, Mo., assignor to Petrolite Corporation, Ltd., Wilmington, Del., a corporation of Delaware No Drawing. Original application May 12, 1939,

Serial No. 273,221. Divided and this application October 23, 1939, Serial No.- 300,843

4 Claims. (Cl. 252-334) This invention relates primarily to the treatwords, they form either true solutions or sols. ment of emulsions of mineral oil and water, such For purpose of convenience, they will be'herein as petroleum emulsions, for the purpose of sepreferred to as water-soluble without any effort arating-, the oil from the water, the present apto indicate whether the solution is molecular or 5 plication being a division of my pending applicacolloidal in nature. The green acids, as indicated 5 tion Serial No. 273,221, filed May 12, 1939. by their name, frequently give an aqueous solu- The object of my invention is to provide a novel tion having a dark green or grey-green appearprocess for resolving petroleum emulsions of the ance. They generally appear as a component of water-in-oil type, that are commonly referred to the acid draw-01f and do not remain behind disas-cut oil, roily oil, emulsified oil, etc., and solved in the oil fraction which has been subwhich comprise fine droplets of naturally-occurjected to sulfuric acid treatment. The green ring waters or brines dispersed in a more or acids are not soluble in oil, even when substanless permanent state throughout the oil which tially anhydrous, and certainly are not soluble constitutes the continuous phase of the emulsion. in oil when they contain as much as of wa- 15 Briefly described, my process consists in subter. Similarly, their salts obtained by neutraliza- 15 jecting an emulsion of the kind mentioned to the tion with a strong solution of caustic soda, causaction of a treating agent or demulsifier consisttic potash, or ammonia, are not oil-soluble. For ing of a certain kind of amine salt derived from convenience of classification, the ammonium salt water-soluble petroleum sulfonic acid or acids of will be considered as an alkali salt.

the kind hereinafter described. In contradistinction to the hydrophile green 20 Petroleum sulfonic acids are produced from a acids, there occurs, as in the manufacture of wide variety of petroleum distillates or petroleum medicinal white oil, the oil-soluble type or the fractions, and in some instances, they are promahogany acids. These mahogany acids are duced from the crude petroleum itself. When characterized by being soluble in oil, especially produced from crude petroleum itself, it is cuswhen anhydrous, and being soluble in oil, even if 25 tomary to use crude oil of the naphthene type, they contain some dissolved water. Some of the crude oil of the paraflin type, crude oil of the mahogany acids also show limited hydrophilic asphaltic type and mixtures of said three difierent properties to the extent that either some water types of crude oil. can be dissolved in the acids, or they, in turn,

The art of refining petroleum crude or various may dissolve to some extent in water. In some 0 fractions, using sulfuric acid of various strengths, instances their salts, such as the sodium, ammoas well as monohydrate and fuming acid, is a mum, or potassium salt, will dissolve in water, well known procedure. In such conventional reto give a colloidal sol. However, regardless of fining procedure, petroleum sulfonic acids have the presence of any hydrophilic properties whatbeen produced as by-products. For instance, in soever, they always have a characteristic hydro- 55 by being water-soluble or dispersible. In other are completely devoid of any solubility in water 55 removing the olefinic components, it has been phobe property, as indicated by the fact that the common practice to' use sulfuric acid, so as to substantially anhydrous form,.for instance, their polymerize the olefines or convert them into sulalkali salts containing 5-12% water, will dissolve" ionic acids which are subsequently removed. in oil. This clearly distinguishes them from the I 40 Likewise, in the production of white oil or highly green acids previously referred to, because the' 40 refinedlubricating oils, it has been customary to green acids in similar form ontain ng he same treat with fuming sulfuric acid, so as to eliminate m unt of Wa er, for example, will not dissolve certain unde irabl components. in oil. The green acids, as such, are essentially In recent years, certain mineral oil fractions hydrophilic a ydmp fl c i cha acter. have been treated with sulfuric acid with the The utility of the maho'ganyacids in various 45 primary object of produci'ngpetroleum sulfonic arts has been enhanced by increasing theirvvaacids, and in such procedure the petroleum sulter solubility; for instance, converting the mafonic acids represented the primary objects of hogany acids into hydroxy alkylamine salts. .On reaction, rather than concomitant by-products. the other hand, as far as I am aware, no valuable 5o Petroleum sulfonic acid, regardless of whether pr du t of c mmerce has resulted from decreas- .50

derived as the principal product of reaction or as ing the water solub i y of -m g y a ids w a by-product, can be divided into two general by the addition of some oil-soluble basic amine, types, to wit, green acid or acids and mahogany such, for example, as triamylamine. The tri-v acid or acids. The green acids are characterized amylamine salts of mahogany acids, for example, r

' acids; etc.

which the alkali salts may have exhibited and show, as would be expected, an increased solubility in hydrophobe solvents.

Green acids are hydrophile in character, as previously stated. Their hydrophile character has been increased by neutralization with materials such as triethanolamine and the like. Such green acid salts having enhanced water solubility, as compared with the ordinary alkali salts, have found application in certain arts.

I have found that when green acids, 1. e., the oil-insoluble type, are neutralized with a diamine of the kind hereinafter described, so as to produce a water-insoluble product, that the resulting material, even though it does not exhibit any marked oil solubility, especially when it contains 5-10% of water, still has pronounced value as a demulsifier for oil field emulsions, either when used alone, or in conjunction with other known demulsifying agents. I employ diamines of the kind derivable most readily by reactions involving an aldehyde and a secondary amine, all of which is hereinafter described in detail. I have also found that sometimes such amine salt of green acids will mix in with a hydrophobe material and a hydrophile material, so as to produce a homogeneous mixture. The effectiveness of the above described material or composition of matter as a demulsifying agent for oil field emulsions appears to be related to some factor other than its solubility characteristics.

The new composition of matter that is employed as the demulsifier in my process, is represented by amine salts of hydrophilic, non-hydrophobic green petroleum acids, as exemplified by the salt derived from such green acids by neutralization with the diamine obtained by reactio'n between two moles of diamylamine and one mole of formaldehyde or one mole of acetaldehyde. The manufacture of said composition of matter involves nothing more or less than neutralizing one mole of the selected petroleum acid with a mole of a suitable amine, or neutralizing two moles of the selected petroleum sulfonic acid with one mole of the amine, in that the amine being a diamine, is dibasic. In the latter case, a suitable indicator, such as methyl orange indicator, may be employed. For purposes of convenience, I prefer that the selected petroleum sulfonic acid contain not over 15% of water. It is understood, of course, that the conventional procedure, employing double decomposition instead of direct neutralization, can be utilizedin the manufacture of my new material or composition of matter. For instance, the sodium salt of the selected petroleum sulfonic acid can be dissolved in alcohol or other suitable solvent, and the amine hydrochloride added so that sodium chloride will precipitate. After filtering off the precipitated sodium chloride, the alcohol can be evaporated and the amine salt recovered. If desired, a mixture of amines instead of a single amine may be employed.

It is well known that certain monocarboxy organic acids, containing approximately eight carbon atoms or more, and not more than thirtytwo carbon atoms, are characterized by the fact that they combine with alkalies to produce soap or soap-like materials. These detergent-forming acids include fatty acids, resin acids, petroleum For the sake of convenience, these acids will be indicated by the formula R.COOH.

It is also well known that diamines, having pronounced basic properties, may be derived by various means, provided that the resultant diamine is characterized by the fact that the two amino nitrogen atoms are not attached to the same carbon atom. Such diamines, generally referred to as alkylene diamines, are well known and may be characterized by ethylene diamine. Derivatives of the diamines herein contemplated are characterized by being a methylene diamine derivative, i. e., a derivative of the hypothetical methylene diamine Methylene diamine is almost unknown for practical purposes, since it is very unstable in the form of a free base, but does exist in .the form of alkylated or acylated derivatives. In view of this fact it becomes obvious that the new chemical compound or composition of matter previously referred to must necessarily be obtained indirectly, insofar that the parent diamine is almost non-existent.

It is well known that a large number of secondary amines are available, which may be designated by the formula type:

in which B represents an alkyl, aralkyl, alicyclic, alkylol, aralkylol, hydroxy alicyclic, heterocyclic, or other equivalent radical. B and B jointly may represent one radical, as in piperidine.

It is well known that aldehydes, particularly the aldehydes of relatively low molecular weight, such as formaldehyde, acetaldehyde, aldol, furfural, benzaldehyde, hexahydrobenzaldehyde, phenyl-acetaldehyde, etc., can combine with two moles of a secondary amine, so as to yield a methylene diamine, characterized by the fact that the two amino nitrogen atoms are attached to the same carbon radical. Such reaction may be indicated in the following manner:

The amine so produced may be indicated by the following formula:

111 which, as hasbeen previously pointed out, T may represent a hydrogen atom derived from formaldehyde, or may represent a radical derived from acetaldehyde, propionaldehyde, butryaldehyde, heptaldehyde, lauric aldehyde, palmitic aldehyde, or stearic aldehyde.

Similarly, instead of aliphatic aldehydes, one may employ heterocyclic aldehydes, such as furfuraldehyde, or aromatic aldehydes, such as benzaldehyde. Unsaturated aldehydes, such as acrolein, crotonaldehyde, or tiglic aldehydes, may be employed. As previously indicated, B represents a radical, such as the methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, decyl, hexadecyl, octadecyl, or a similar radical. Similarly, B may represent an aralkyl radical, such as a benzyl radical, ethyl benzyl radical, dimethyl benzyl radical, an alicyclic radical, such as the cyclohexyl, methyl cyclohexyl, etc.; likewise, B may represent a hydroxy ethyl, hydroxy ,propyl, hy-

droxy butyl, and similar radicals, such as a CsH4C2H4OH radical, or a CsHioOH radical. Other radicals include the furfural radical, or hydroxy derivatives thereof. Piperidine may be considered as a special adaptation in which one radical replaces two amino hydrogen atoms.

It is to be noted that the methylene diamine, expressed by the above formula, is a tertiary diamine in the sense that neither amino nitrogen atom has attached thereto a replaceable hydrogen atom. For convenience, the above formula may be rewritten as follows, so as to indicate such instances where there is present an alcoholic hydroxyl radical: 4

in which B'OH is obviously the monovalent hydroxy hydrocarbon radical, such as an alkylol radical or the like. Needless to say, B'OH may occur more than once, and B may occur less than three times. It is well known that amines such as triethanolamine or the like can be acylated by reaction with fatty acids or a suitable functional derivative thereof, such as the acyl chloride or the anhydride, or even the ester. If the tertiary hydroxy methylene diamine of the kind just described is reacted with a detergent-forming monobasic carboxy acid, the reaction may be indicated in the following manner:

with the formation of an intermediate ester which may be indicated in the following manner-:

In addition to aldol, other similar hydroxy aldehydes or aldehyde-alcohols maybe employed.

As to such aldehydes other than aldol, reference is made to Richter's Organic Chemistry, volume 1, third English edition, 1934, pages 389-391.

In view of what has been said previously, it does not appear necessary to enumerate various suitable amines which may be employed, but it may be well to indicate that'among those which may be employed are the following: diethanolamine, dipropanolamine, dibutanolamine, dipentanolamine, dioctanolamine, glyceryl dihexanolamine, methyl glycerylamine, ethyl glycerylamine, propyl glycerylamine, cyclohexyl glycerylamine, benzyl glycerylamine; dibenzylamine, ethyl bentzylamine, methyl benzylamine,- propyl benzylamine, cyclohexyl ethylamine, cyclohexyl propylamine, cyclohexyl hexylamine, diethylamine, dipropylamine, diamylamine, dihexylamine, dioctylamine, diglycercylamine, etc. In all the previous examples, each radical indicates a substituent for an amino hydrogen atom. Similarly, amines can be obtained from polyglycerols or polyglycols, as for instance, the secondary amines, indicated by the following formulas:

Such amines may serve as functional equivalents of the previously described amines, which happen to be free from an ether linkage. Likewise, one may have amines in which there is more than one ether linkage, i. e., in which the hydrocarbon radical, which replaces an amino hydrogen atom, has been interrupted more than once by an oxygen atom. 1

In examining the previous formulas, it becomes evident that if two different amines are employed, the reaction is not limited to the two dissimilar amines, but may take place in part in such a manner as to involve two similar amines. In other words, if the two different amines be indicated as A and B, the reaction is not limited to the diamine involving both A and B, but in part the diamine will be formed solely from two molecules of A, and in part solely from two molecules of B. For practical purposes,'then, it is most expedient, in the majority of instances, to manufacture or produce a methylene diamine froma single kind of secondary amine; and in such event, everything else being equal, it is most desirable to use the cheapest secondary amine available that will produce at least a fairly water-insoluble product, and the cheapest aldehyde available. I particularly prefer to use diethanolamine and to completely or at least partially esterify the diethanolamine with a long chain carbon atom acid, particularly a detergent-forming acid, having at least 8 carbon atoms and not more than 32 carbon atoms, such as oleic acid, naphthenic acid, or abietic acid. Naturally, the introduction of one or more of such long chain carbon compounds greatly increases the oil solubility of the amine; and such oil solubility is transposed, at least in part, to the final product, which is a salt of the sulfonic acid. As previously pointed out, it is not believed that oil solubility per se is the index as to effectiveness of the demulsifying agent. One may, of course, employ the hydroxylated diamine without acylation', but in such event, my experience has been that it is more preferable perhaps to employ diamylamine. Similarly,attention is again directed to the fact that wherever hydroxyl radicals exist, then such hydroxy] radical might be reacted with an acid having less than 8 carbon atoms, for instance, acetic acid, butyric acid, heptoic acid, etc. More than one hydroxy' early stages to prevent the reaction from taking place too rapidly, and with a slight application of heat during the latter stages, so as to obtain complete reaction.

The methylene diamine so obtained may be indicated by the following formula:

If desired, of course, the product obtained by reaction can be purified in the customary manner, so as to remove any unreacted aldehyde, and also any unreacted simple secondary amine. However, if the reaction is conducted carefully a substantial and generous yield of the desired diamlne is obtained, and it is unnecessary to resort to any purification. It has been previously pointed out that having obtained an amine of the kind desired, it is only necessary to proceed to neutralize the green acid, as previously indicated.

Incidentally, it may be well to point out that one particularly desirable mixture of diamines is obtained. by employing one mole of diethanolamine and one mole of diamylamine in connection with one mole of acetaldehyde. The resultant product so obtained will average two hydroxyl radicals per molecule; and one hydroxyl radical can be readily eliminated by acylation with one mole of a selected acid, particularly oleic acid or naphthenic acid. If desired, both hydroxyl radi cals may be eliminated. In this instance the lon carbon chain attached to an amino nitrogen atom is interrupted by an oxygen atom. It is understood in the hereto appended claims that reference to a hydrocarbon radical includes such radicals that are essentially hydrocarbon in nature, which include carbon atom chains that are interrupted at least once by an oxygen atom. This would occur, of course, in linkages such as the following:

where R is the hydrocarbon radical derived from naphthenic acid, oleic acid, aaetic acid, heptoic acid, or the like. Acylation can be accomplished by any suitable acid compound, such as the acyl chloride, the anhydride, etc. If an amine salt is formed, such as the hydrochloride, it must be converted into a base by conventional treatment with strong caustic soda or the like.

Returning momentarily to the preparation of the preferred reagent, no additional information is required. However, it may be well to point out that I prefer to use a green acid selected so that it is relatively free from inorganic acid, such as sulfurous acid and sulfuric acid, and containing not over 15% water, and preferably, as little unsulfonated hydrocarbon material as possible. A convenient amount of such material, for instance, a thousand pounds, is neutralized with a diamyl diamine previously described, so that the resultant compound indicates neutral or slightly basic to methyl orange, or some other acceptable indicator.

It may be well to point out that hydrophile nonhydrophobe petroleum sulfonic acid or acids of the green acid type vary somewhat; for instance, the molecular weight may vary within the range of 350-500 or thereabouts. Naturally, these petroleum sulfonic acids may carry some polymerized olefines, free hydrocarbons, or the like, or may even carry a bit of naphthenic acids which represent carboxylated non-sulfonated petroleum acids. As previously stated, these materials are well known commercial products, and are available in the open market, either in the form of the acid itself, or in the form of a salt.

In the claims the amine or, more specifically, the diamine, is referred to as basic to indicate that the basicity is in the neighborhood of that of ammonia, triethanolamine, or amylamine. In some instances the basicity may be somewhat greater, in fact, perhaps considerably greater, and in some instances perhaps slightly less. In order to insure such basicity, it is necessary that there be no aryl or aromatic radical attached to the amino nitrogen atom from which the diamine is produced. In other words, such materials as phenyl amylamine, diphenylamine, phenyl octylamine, etc., are not satisfactory, due to the presence of the aromatic phenyl radical or an aryl radical, such as the naphthyl radical attached directly to the amino nitrogen atom. In the event that such aryl radical is attached to the amino nitrogen atom, the basicity of the amine is reduced to that of the aniline, or the like. Such amines of low basicity do not form stable salts with the petroleum acids 'of the kind described. For this reason the expression basic non-aryl is employed to clearly characterize the amine. The term sulfonic acid used in the claims is intended to refer to a substance consisting either of a single acid or a mixture of acids.

The new process that I .have devised for resolving or breaking petroleum emulsions of the water-in-oil type involves subjecting the emulsion to the action of a demulsifier consisting of the above described new material or composition of matter. Said material is used either alone or in admixture with another or with other conventional demulsifying agents, and its method of use is the same asthat generally employed in resolving or breaking petroleum emulsions of the water-in-oil type with a chemical demulsifier. Briefly stated, the conventional method of using a chemical demulsifier to break a petroleum emulsion consists in introducing the demulsifier into the well in which the emulsion is produced; introducing the demulsifier into r. conduit through which the emulsion is flowing; or introducing the demulsifier into a tank in which the emulsion is stored. After treatment the emulsion is allowed to stand in a quiescent state, usually in a settling tank, and usually at a temperature varying from atmospheric temperature to about 200 F., so as to permit the water orv brine to separate from the oil, it being preferable to keep the temperature low enough to prevent the volatilization of valuable constituents of the oil. The amount of demulsifier that may be required to break the emulsion may vary from 1 part of demulsifier to- 500 parts of emulsion, up to 1 part of demulsifier to 20,000 or'even 30,000 parts of emulsion.

I desire to point out that the superiority of the reagent or demulsifying agent contemplated in my process is based upon its ability to treat certain emulsions more advantageous-1y and at a-somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described will find comparatively limited applica-.

tion, so far as the majority of oil field emulsions are concerned; but I have found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with, the demulsifying agents heretofore available,

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A process for resolving petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifier, comprising a water-insoluble salt of a basic,

mono-methylene diamine of the formula type:

-a hydroxy hydrocarbon radical, in which the acylating compound is derived from an acid containing not more than 32 carbon atoms; said diamine salt being obtained from water-soluble, non-hydrophobe petroleum sulfonic acid of the green acid type.

2. A process for resolving petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifier, comprising a. water-insoluble salt of a basic, mono-methylene diamine of the formula type:

in which T is selected from the class consisting of hydrogen atoms, hydroxy hydrocarbon and hydrocarbon radicals; and B is a non-aryl hydrocarbon radical; said diamine salt being obtained from water-soluble, non-hydrophobe sulfonic acid of the green acid type.

3. A process for resolving petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifier, comprising a water-insoluble salt of a basic, mono-methylene diamine of the formula type:

petroleum in which T is selected from the class consisting of hydrogen atoms, hydroxy hydrocarbon and hydrocarbon radicals, and B is a non-aryl hydroxy hydrocarbon radical; said diamine salt being obtained from water-soluble, non-hydrophobe petroleum sulfonic acid of the green acid type.

4. A process for resolving petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifier, comprising a water-insoluble salt of a basic, mono-methylene diamine of the formula type:

MELVIN DE GROOTE. 

